With a voice response system, a telephone user uses the telephone's Dual-Tone Multi-Frequency (DTMF) keypad to communicate the user's desired actions to a Telecommunication Central Office. The Central Office receives the digits and responds with the appropriate actions. When a voice response is required for additional information, a Voice Response Announcement System is connected through the Central Office to the user.
The problem arises when speech patterns sent to the user from the Voice Response Announcement System contain audio frequencies that are similar to valid DTMF tones. These frequencies can cause the Central Office to interpret these as a valid DTMF tone and take an inappropriate action. Prior to the present invention, there was no means of testing the outgoing messages for these unintentional embedded tones.
Therefore it is the objective of the present invention to provide circuit that can screen announcement messages from the Voice Response Announcement System and determine if the messages contain tones that could be misinterpreted.